1. Field of the Invention
This invention relates to resolver circuitry for providing an excitation signal to a resolver and processing an angular position signal from the resolver to compensate for manufacturing tolerances and temperature variations in the application of the resolver.
2. Description of Prior Art
Known function generators (resolvers) provide a rotor winding typically excited with a low frequency alternating current and have a plurality of stator windings which provide signals from which the angular position of the rotor may be determined. Naturally, both angular velocity and acceleration of the rotor may be easily determined. A microcomputer may be employed to provide an appropriate output indicative of angular position, velocity and acceleration. The rotor or exciting winding may be energized through an adjustabale transformer which in turn is energized by a signal generator. Such a function generator is described in West German patent application DE No. 34 32 395.
Economical function generators often have relatively large air gaps between their stator and rotor windings. Likewise, relatively large air gaps are often present between the primary and secondary windings of an associated adjustable transformer. Consequently, relatively high input voltage or power is typically employed to energize the primary winding of an associated adjustable transformer. When employed in varying ambient temperatures of relatively wide range, the variance in temperature can lead to significant alteration of the signal provided by the stator windings. As a result of the variation in the stator signals, erroneous indication of the angular position, velocity and acceleration of the rotor, may result.